Del Mar Inn
Ask for the reduced UCSD rate. 6 miles north of UCSD. Shuttles will leave from the hotel at 830am to take you to campus. Alternatively, take the MTA 101 bus ($1.75, exact change required) to campus.
San Diego Marriott La Jolla — 1.5 miles from campus.
A few more options are in La Jolla, 30 minutes away on the MTA 30 bus ($2.25, exact change required):
La Jolla Shores (kinda pricey and rooms are not always available consecutively)
8110 Camino Del Oro La Jolla, CA 92037
Ask for UCSD/Physics rate; mention Peggy McCoy for reference